Differential Expression of Human Cytomegalovirus MicroRNAs in Triple-Negative Breast Cancer Tumors
Dr. Perpetua Muganda
Triple-negative breast cancer (TNBC) remains one of the most challenging subtypes of breast cancer. It is characterized by the lack of expression of the estrogen and progesterone receptors, as well as the human epidermal growth factor receptor 2 (HER2/neu). TNBC accounts for 15-20% of all breast cancer cases, and possesses a high recurrence and death rate as compared to other breast cancer subtypes. The molecular basis of TNBC oncogenesis is currently unknown. Since cellular miRNAs have been implicated in TNBC oncogenesis, it is possible that viral miRNAs may also play a role in the aggressiveness and poor prognosis of these tumors. In fact, human cytomegalovirus (HCMV) antigens have been found preferentially in breast tumors as compared to normal controls. Thus, the objective of this research was to determine the prevalence and differential expression of HCMV miRNAs in TNBC tumors compared to control normal samples. We conducted a comprehensive profiling of known HCMV miRNAs in 57 TNBC basal tumors as compared to 16 control normal breast tissues. Publicly available deep sequencing data obtained from the Sequence Read Archive database were analyzed utilizing the Chimira pipeline, Morpheus heat-map software, and graphical representation. Three HCMV miRNAs (UL22A-3p, UL59, US29-5p) were significantly expressed in 14-32% of the TNBC tumors, and not in control normal breast tissue. One HCMV miRNA (US25-1-5p) was significantly expressed in 21% of the TNBC tumors as compared to 6.25% of normal control breast tissue. The prevalence of US25-2-3p was decreased in TNBC tumors as compared to control normal cells; US25-2-3p was present in 50% of the control samples and 17.5% of the TNBC tumors. This is the first report on the differential expression of known HCMV miRNAs in TNBC tumors. Our findings suggest that these deferentially expressed HCMV miRNAs may potentially play a role in the pathogenesis of TNBC.
Gray, Jalynn, "Differential Expression of Human Cytomegalovirus MicroRNAs in Triple-Negative Breast Cancer Tumors" (2019). Undergraduate Research and Creative Inquiry Symposia. 201.